Abrading machines



Dec. 25, 1956 o. w. DILLON ABRADING MACHINES 2 Sheets-Sheet 1 FiledApril 14, 1953 INVENTOR oscAR w. DILLON AT TORN E! Dec. 25, 1956 w.D|LLQN ABRADING MACHINES 2. Sheets-Sheet 2 Filed April 14, 1953 INVENTOROsOAR w. DILLON ATTORNEY Unite States atent ABRADING MACHINES Oscar W.Dillon, Sturbridge, Mass, assignor to American Optical Company,Southbridge, Mass, a voluntary association of Massachusetts ApplicationApril 14, 1953, Serial No. 348,710

1 Claim. (Cl. 51-124) This invention relates to surfacing devices andmore particularly to hand surfacing machines such as are used in theophthalmic industry in surfacing lenses or similar articles.

One of the principal objects of the invention is to provide a machine ofthe above character with novel and efficient means for varying the speedof rotation of the abrading tool.

Another object is to provide a hand surfacing machine having a motordriven surfacingtool and readily accessible manually operable means forenergizing and deenergizing the motor as desired.

Another object is to provide means for varying the speed of rotation ofthe abrading tool which is preferably operable when the machine is inmotion.

Another object is to provide a machine of the above character whereinthe tool supporting spindle, the tool on said spindle and the abrasivepan are all disposed in axially aligned relation with each other and aretilted forwardly to facilitate greater ease to the operator inperforming the abrading operation and to cause the abrasive used duringsaid abrading operation to collect in the front of the abrading toolwhereby it is more readily accessible to the operator.

Other objects and advantages of this invention will become apparent fromthe following description taken in connection with the accompanyingdrawings and it will be apparent that many changes may be made in thedetails of construction and arrangement of parts without departing fromthe spirit of the invention as expressed in the accompanying claim. I,therefore, do not wish to be limited to the exact details ofconstruction and arrangement of parts shown and described as thepreferred form only has been given by way of illustration.

Referring to the drawings:

Fig. 1 is a top plan view of the device embodying the invention;

Fig. 2 is an enlarged side elevational view of said device shownpartially in section;

Fig. 3 is an enlarged fragmentary sectional view taken as on line 33 ofFig. l and looking in the direction indicated by the arrows; and

Fig' 4 is a fragmentary side view of the motor driven pulley showing aportion thereof in section.

Referring more particularly to the drawings wherein like characters ofreference designate like parts throughout various views, the deviceembodying the invention comprises a base 6 having an attachment seat 7,adjacent the rear thereof, provided with a web 8 having a centralopening 9 therein to which is secured a motor 10 by bolts or othersimilar means 11. The motor 10 has a shaft 12 which extends internallyof the base and on which is mounted an expansion pulley 13. The pulley13 has a stationary part 14 having an inner cone-shaped side surface 15and a movable part 16 also having an inner cone-shaped surface 17. Themovable part 16 is mounted to slide longitudinally of the shaft 12 andis restricted in its movement by a coil spring 18 carried by the shaft.The coil spring is interposed between a flange 19 mounted on the end ofthe shaft 12 and the outer central side surface of the movable member16. A housing 20 is provided on said member 16 in overlying relationwith the coil spring 18 and in sliding engagement with the flanged end19 of the shaft.

The pulley 13 is connected with a pulley 21 mounted on the lower end ofa spindle 22 through a belt 23. The belt 23 has a wedge-shaped crosssection for engaging the respective inner cone-shaped surfaces of theportions 14 and 16 of the pulley 13 and for engaging a taperedcircumferential channel 24 formed in the face of the pulley 21. Thepulley 21 is secured to the spindle 22 by a set screw or the like 25.The spindle 22 is mounted within a pair of spaced bearings 26 and 27 andhas a tapered upper end 28 adapted to detach-ably receive an abradingtool or lap 29. The bearings 26 and 27 are carried by a supportingmember 30 secured, as by bolts or the like 31, to a plate 32. The plate32 rests on a pair of angularly disposed slide plates 33 secured to theupper wall 34 of the base 6 by screws or the like 35. The upper wall 34is provided with an opening 36 through which the spindle and bearingsupport 30 extends.

The plate 32 is pivotally connected at 37 to the upper wall 34 of thebase 6 as shown best in Fig. 1. The plate 32 further has a block 38secured thereto as by screws or the like 39. The block 38 is adjustablysecured to a tie rod 40 by a ball and socket connection 41. The tie rod40 is secured to a crank lever 42 by a ball and socket connection 43similar to the connection 41. The crank lever 42 is connected to a shaft44 rotatably supported in a bearing 45 in the side wall of the base 6. Ahand lever 46 is attached to the outer end of the shaft 44 to providemanually operable means for rocking the crank lever. The bearing 45 issecured to the side wall of the housing by screws or the like 47.

The plate 32 has a rim 48 secured throughout the contour edge thereofand said plate has a cylindrically shaped housing 49 secured thereto byscrews or the like 50. The housing 49 has an inwardly turned upper edgeportion 51 to provide an inwardly disposed lip for supporting the upperrim portion 52 of an abrading pan 53. The abrading pan 53 has a centralupwardly disposed tubular portion 54 fitted about the shank 55 of a toolor lap 29 and lying beneath said tool or lap. The rim 48 is providedwith an upwardly extending bearing portion 56 in which is slidablymounted a sleeve 57 having a flange portion 58 on the upper end thereof.The sleeve 57 may be raised or lowered in the bearing 56 and is held inadjusted position by a clamp screw 59. Inwardly of the sleeve 57 thereis rotatably mounted a spindle 60 having its upper end attached inwardlyof the neck 61 of a yoke 62 by a pin or the like 63. The spindle has itslower end threaded to receive a nut 64 which is adapted to preventlongitudinal movement of the spindle relative to the sleeve 57 whilepermitting rotation thereof. The yoke 62 has a split collar 65 pivotallyattached thereto, as illustrated at 66. The split collar 65 slidablyreceives a manually operable lever 67 which may be adjustedlongitudinally of said collar and held in desired position of adjustmentby a clamp screw 68. The lever 67 has a longitudinal bore 69 throughwhich there is extended wires 70 connected adjacent one end thereof to atrigger type switch 71 carried by a handle 72 mounted on the free end ofthe lever 67. The wires '70 are connected to the motor 10 and also to asuitable source of electrical energy, as by the lead 70a, whereby theturning off or on of said switch 71 will energize or de-energize themotor 10.

The lever 67 has a perforated block 73 secured thereto Patented Dec. 25,1956 intermediate its ends. The block 73 has. a lens block pin 74extending therethrough, as shown by Fig. 2. The pin 74 has a recessedflattened side 75 adapted to be engaged by a clampscrew 76 whereby thepin may-be raised or lowered relative to said block and secured inadjusted position by'said clamp screw. The lower end ofthe pin has atapered: tip 77' secured thereto and adapted" to engage with the taperedsocket 78 of a lens block 79. The lens block 79 has a lensblank 80 to beabraded secured thereto by a layer of pitch or other suitable adhesive8:1.

The lever 67, block-73yand handle 72'are preferably formed ofa-heavy'm'etalrand are sodi'mensione'd as to introduce substantially theweig'hd desired to' be exerted on: the lensblank during the: abradingoperation, however, the operator may increase the pressure on the lensblank by exerting manual pressure onthe lever.

The motor 10,betweeniit and the web 8, is provided with suitable:cushioning means 82; such as a layer of synthetic rubberor other:suitable means;

Asshownin Figs. 1 and 2, the axes of the spindle 22, lap 29: and pan53.,areinsubstantiallyconcentric relation with each other and arel'allitilted: forwardly so as to cause the pan 53 to. angle forwardly anddownwardly'whereby the abrasive usedv during the abrading: of the lensblank- 80 will settle, in theforward end'ofv the pan 53 under the actionof gravity, at. a. location: forwardly of the. lap 29 asdiagrammatically illustrated. at 83. This arrangement furtherw aidstheoperator during the abrading of the lens blank, as it permitsmoreofia plan view ofthe lap 29 and the relation of the. lens blanktherewith-during the abrading operation andv which'is under the manualcontrol of the operator;

The split pulley 13; and pivotal-conneetion of the plate 321 with the.upper" wall. 34 of the base 6' is to enable changing-:the. speed ofrotationof the tool-or lap supporting: spindle 22. Thisl is.accomplished by first energizing the motor 10 by manipulationzof theswitch 71 whereby thepulley. 13 will be rotated and will; in turn,rotate the pulley- 21. through. the: belt. connection 23. When theplate32:and the associatediparts of'the device carried thereby is:adjustediab out the. pivot .37 by: pro'perrnanipm lation:of'.the:lever46 totherearmost position,'.a's shown infullelinesiinzFig; l, the.policy 13? will befunctioning effectively at P its maximum. diameter: asshown by the re lated..positioniof. the belt2-3iiwith said pulley inFig. 2, The speed of the motor and the related 1 diameters i of 1 therespective pulleys; 13 and 21 areso controlled that when the device is:-adjusted, as: shown in Fig.2; the=speed of the spindlezz will beapproximately8f75 R. P. Mr How'- ever, if it is. desired to reduce-thespeedof rotationof thet'spindle 22,.the-lever 46amaybepulledin -a;forward direction. When moved. to;this 'position, the crankdever 4-2andthe link connection thereof-with =the block- 38 on therplate- 32 willcausesaid 'plate'. and the associated parts of. the .device carriedtherebyv to :be swung forwardly about the pivot 37. to apositionzasrindicated-by-the dash line 84in Fig; 11 This will exert a'pull-onthebelt23 of anaamountsufiicient to cause the portions 14=arrd 16 of the. splitpulley 13 to'spread. relative to' eaehother against the resilient actionof the-icoil spring 18, asshown in. Fig.1 4; whereby the effective.diameter of th'epulley 13 is decreased thereby-causing-the speedof-the:-pulley 21 to beproportionatelydecreasedi Theratio of'di-fferenceiis such asto introduce asuhstantial 2-ito-l chan'ge wherebythe speed of rotation ofIthe -spindle ZZmay be broughtdowntoapproximately 400 R. PL M'.

Machines of the character described are=used both for grinding andpolishing lenses' and' are particularly adapted for use in roughingoutstrong curved 'blanks to the approximate shape desired; This isaccomplished with theuse-ofa coarserabrasivemanually"fed o to the lapwhile the blank is being manually rocked by proper manipulation ofthe-lever"67':'

It has been found in the past that difficulty has been encountered inrocking strong convex curves to the approximate shape desired in thatthe lens and holder jump off the lap particularly when a steep concavetool is being used and if the speed of the rotation of the tool is toogreat. This difiiculty is mostly. encountered at the start of thegeneration of the steep curve in that the lens blank tends to grabthellap and it is difiicult to manually hold the lens on the lap evenwith controlled pressure being applied on the hand lever 67. The presentmachine therefore, provides an initial relatively slow rotation of thelap which speed of rotation can be increased as the excess material hasbeen ground off the blank and the blank becomes more positively seatedto the shape of the curve being generated. This initial slow speedgreatly reduces the difficulty in maintaining the blank in abradingrelation with the lap and the subsequent increase in speed of rotationof the lap enables the" reducing of the grinding cycle. The increasedspeed is furthermore desirable for polishing.

It is further pointed out that the change in the speeds of rotation? ofthe spindle 22' is brought about by changingthe distance between thedrive shaft 12 of the motor and saidspindle 22; When. this charge takesplace, the spindle 22, base plate 32, housing 49, abrasive 12211153, andthe manually operable lever 67', together with its associated parts,al1:movea-s a unit with-respect to the base 6. The openingdfi providesclearance whereby this move ment will take place about thepivot 37 withthe base piate 32 slidably engaging the slide blocks 33'. Due totheefact that the connection of the crank lever 42 with the tie rod 40and theconnection of said tie rod 40 with the=block 38 carried-bythebaseplate 32 are of ball-and socket type, this adjustment may bebrought about by merely swinging.- the lever 46 rearwardly or forwardlywhen the machine is in operation From the foregoing description it willbe seen that simple, efficient, and-economioaL means have been providedfor-accomplishingall of the-objects and advantages of the inventio Iclaim:

A lens surfacing device of the character described adapted to besupported upon a Work bench or the like during use thereof, said devicecomprising an elongated hollow base of shallow depth and having aforwardly and downwardly inclined top wall, said wall at theforward partthereof being'of appreciable width and having a relatively large openingtherein, a plate overlying said opening and pivotally attached to saidbase at one side of saidopening,-bearing means carried by said plate, aspindle rotatably mounted'in said bearing means and eittending throughsaid' openiflg, said plate and bearing means; supporting said spindle inan upwardly and forw'ardly' inclined'po'sitio'n, a lap on the upper endof said spindle, a pulley on the lower end of said spindle and enclosedwithin the forwardpart of said hollow base, a pan carried by said plateand'surrounding said lap andupper part of said spindle, the bottom ofsaid pan being disposed'insubstantially parallel relation to said topwall so as to. cause abrasive material being used by the device tocollect in the lower forward portion thereof, a manually operable leveruniversally pivotally connectedat its rear end to supporting'ineanssecured to said base, and extending forwardly'acrossthe top of said panto a locationabove' the'fo'rward portion of said base, said lever havingaha'nd grip at itsfoi'ward end and carrying dependingmeans'intermediateits-opposite ends for retaining alens blankin operative engagem'entwithsaid lap, a'inotor carried by a rearpart of-said base and having itsdrive shaft extending downwardlyth-rough a smaller opening in said topwall, said'drive shaft being disposed in substantially parallel relationto said rotatable spindle, a clr-iv pulley on'saiddi ive*"sh'aft withinsaid hollniv" base; a drive 'belti' offconstant lengthfeatending: aboutsaid drive pulley and saidpulley"on"-said=spindle; a" second manuallyoperable lever pivotally carried by said base and having link meansconnected thereto and to said plate at a point spaced from the pivotalconnection of said plate to said base so as to allow said second leverto swing said plate relative to said base for varying the distancebetween said spindle and said drive shaft, one of said pulleys havingmeans connected thereto for varying the effective diameter thereof inresponse to a change in distance between said spindle and said driveshaft, whereby the speed of rotation of said lap may be selectivelyvaried by movement of said second lever, said hand grip on said firstlever having a trigger-like electrical switch positioned thereon forcontrolling the operation of said motor, and electrical means extendingfrom said switch to said motor for electrically connecting said motor toa source of electrical energy, said first and second manually operablelevers being disposed adjacent opposite sides of said pan so as toenable an operator of the device to conveniently simultaneouslymanipulate both of said levers when desired while in front of the deviceand observing the lens surfacing operation being performed thereby.

References Cited in the file of this patent UNITED STATES PATENTS1,256,256 Pryor Feb. 12, 1918 1,679,199 Baker July 31, 1928 2,189,288Heyer Feb. 6, 1940 2,191,200 Heyer Feb. 20, 1940 2,262,721 Flygare Nov.11, 1941 2,291,629 Jackson Aug. 4, 1942 2,435,320 Metzger Feb. 3, 19482,488,834 Simpson Nov. 22, 1949 2,581,683 McEwan Jan. 8, 1952 2,616,226Avaucour-t Nov. 4, 1952 2,619,842 Felix Dec. 2, 1952

